Author : Suhardi

Summary : The study determined the effects of soil type, superphosphate levels, inocula types as well as the combined effects of soil and superphosphate level; soil, and inoculum type and soil; and superphosphate level and inoculum type that favors the initial growth of Pinus merkusii. Seeds were obtained from Bandung, Indonesia. Soils were collected from Caliraya, Kalayaan, Laguna and University of the Philippines Los Ba¤os (UPLB), College of Forestry (CF), Forest Experimental Plantation, College, Laguna. Seedlings were inoculated with spores of fungi tentatively identified as Pisolithus tinctorius and Rhizopogon sp. or mycorrhizal pine soil one month after germination and then fertilized with superphosphate two months later. Soil type significantly affected diameter growth, root/shoot ratio, and mycorrhizal root formation. Growth of P. merkusii seedlings was better in Caliraya soil than in UPCF soil. Phosphate levels did not affect growth parameters. Inoculum type significantly affected height, diameter, total biomass, root/shoot ratio, number of short roots, and mycorrhizal root formation. Uninoculated seedlings showed significantly greater growth than all inoculated seedlings, but in terms of mycorrhizal formation, mycorrhizal pine soil was best. Combination of soil type and superphosphate levels significantly affected diameter growth. Seedlings planted in Caliraya soil fertilized with 4, 6 and 8 superphosphate per seedling had greater diameter growth than those planted in UPCF soil fertilized with any level of superphosphate. Combination of soil type and inoculum type significantly affected total biomass, root/shoot (R/S) ratio, number of short roots, and mycorrhizal root formation. However, combination of soil types, superphosphate levels, and inoculum type did not affect any of the growth parameters. It was concluded that poor soil like Caliraya soil induced better diameter growth, root/shoot ratio and mycorrhizal root formation of P. MERKUSII than fertile soil like UPCF soil.